Cut-off type wire stripper



970 M. w. BRADLEY 3,532,011

CUT-OFF TYPE WIRE STRIPPER Filed Feb. 8, 1968 I N VENTOR MAR/0N 14/.BRADLEY ATraQA/E y ice Patented Oct. 6, 1970 3,532,011 CUT-OFF TYPEWIRE'STRIPPER Marion W. Bradley, Box 502, 6159 Berkshire Way, Paradise,Calif. 95969 Filed Feb. 8, 1968, Ser. No. 703,998 Int. Cl. H02g 1/12U.S. Cl. 81-95 6 Claims ABSTRACT OF THE DISCLOSURE A lightweight,portable device that may be held in a hand of a user to sever a wire andstrip a section of insulation of predetermined length from an endportion of the cut wire.

BACKGROUND OF THE INVENTION Field of the invention The present inventionrelates to the field of insulation strippers and wire cutters.

Description of the prior art In the past, numerous devices have beeninvolved and used in stripping insulation from a wire to expose a baredend portion of wire that is connected to a terminal or spliced toanother bared end portion of wire. The length of the insulation sostripped from a wire is left to the judgment of the user of the stripperor measurements the user may make.

During the past few years, devices have been developed and come intoextensive use by which a bared end portion of wire of a precise lengthmay be tension wrapped about a connector or terminal to effect anelectrical connection therewith without the use of solder. A bared wireend portion of either too little or too great length impairs the formingof such a tension wrapped connection.

The present invention when used permits a length of insulated wire to becut from a coil, and a section of insulation of a predetermined lengthstripped from an end portion of the cut wire Without relying on thejudgment of the user of the device or measurements he may make.

SUMMARY OF THE INVENTION A portable lightweight device that may be heldin the hand of a user to sever a length of insulated wire, and strip asection of insulation of a desired length from one end of the cut wireportion.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of thecombined wire cutter and insulation stripper;

FIG. 2 is a side elevational view of the device with a length ofinsulated wire extending longitudinally therethrough;

FIG. 3 is the same view as FIG. 2, but after the Wire has been cut;

FIG. 4 is a side elevational view of the device after it has stripped asection of insulation of a predetermined length from an end of a cutportion of the wire; and

FIG. 5 is a longitudinal cross-sectional view of the wire cutter, takenon the line 5-5 of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawing, itwill be seen thatthe combined wire cutter and insulation stripper tool Ais shown in perspective in FIG. 1.

Tool A includes an elongate rigid body that has a first upwardly andrearwardly curved end 12 and a second downwardly and forwardly curvedend 14. Curved ends 12 and 14 are longitudinally spaced a suflicientdistance to permit the body 10 to be gripped in the hand of a user (notshown).

A groove 16 having cutting edges 18 is formed in the first curved end12, and is used for stripping insulation 20 from a wire 22. When edges18 are in engagement with insulation 20, and the wire 22 is pulledforwardly relative to the tool A, the section of insulation rearwardlyof first end 12 is stripped from the wire. The shape of the groove 16 isshown and described in detail in my Pat. No. 3,180,184 entitled WireInsulation Stripper that issued Apr. 27, 1965. Second curved end 14 ispreferably covered with a layer of plastic or other inert material. Whenthe body 10 is gripped in the palm of the hand of a user (not shown) thesecond curved end 14 prevents the body inadvertently slipping therefrom.

Body 10, in addition to defining the cutting edges 18 for strippinginsulation 20 from a wire 22, also serves as a mounting for a wirecutting assembly B, as may best be seen in FIG. 1.

The assembly B includes a rigid rectangular base 24 that is secured tothe upper side 10a of body 10 by a screw 27 or other suitable fasteningmeans. Base 24 is disposed at an intermediate position between curvedends 12 and 14. A clevis 26 extends upwardly from one longitudinal sideportion of base 24. The clevis 26 supports a transverse pin 28 that hasa lug 30 pivotally mounted thereon.

Lug 30 is afiixed to the underside of an elongate pressure plate 32. Thepressure plate 32 has a cutting member 34 extending downwardlytherefrom. The forward edge portion 24a of base 24 tapers downwardly andrearwardly as does a rearward transverse edge surface 34a of cuttingmember 34. Edge portion 24:: and edge surface 34a have substantially thesame radius of curvature 36 that originates at the center of pin 28, asmay best be seen in FIG. 5. The edge surface 34a and a lower surface 34bof member 34 cooperate to define a transverse cutting edge 34:: wherethey intersect.

The edge surface 34a slides downwardly over edge portion 24a when wire22 is severed as shown in FIGS. 3 and 4. The upper extremity of edgeportion 24a is spaced a distance C from the part of the cutting edges 18that engage the insulation 20 when the wire 22 is disposed in tool A asshown in FIG. 2. Upon the cutting member 34 being pivoted downwardlyrelative to base 24, as shown in FIG. 3, the wire 22 is severed, andinsulation 20 stripped from a section 22a of the wire 22, when the wireis drawn forwardly relative to tool A as shown in FIG. 4. The strippedsection 22a of the wire 22 shown in FIG. 4 is of length C.

To prevent the cutting edge 34c being dulled by pressure contact withsurface 10a of member 10, the forward, upper edge portions 26a ofclevises 26 are formed flat to act as stops when cutting member 34 haspivoted to the position shown in FIG. 3. Pressure plate 32 is normallydisposed in the upwardly and forwardly extending position shown in FIG.2 due to a compressed helical spring 38 or other resilient means beingdisposed between base 24 and plate 32. The ends of spring 38 arepreferably positioned in cavities 32a and 24b formed in plate 32 andbore 24 as shown in FIG. 5.

The use and operation of the tool A has been previously described indetail and need not be repeated.

What is claimed is:

1. A portable tool capable of being held in the hand of a user to cut aninsulated wire and strip a section of insulation of a predeterminedlength from the cut portion of said wire, said device including:

(a) an elongate rigid member having a first forwardly disposed curvedend that extends upwardly and rearwardly, said first curved end having agroove formed therein that is bounded by sharpened edges that severinsulation from said wire when in engagement with said insulation andwhen said wire is moved forwardly relative to said member;

(b) a base rigidly afiixed to the surface of said member from which saidfirst curved end extends upwardly, said base having a forward endsurface that has at least a portion thereof longitudinally spaced fromthe part of said sharpened edges that engage said insulation at saidpredetermined length;

(c) a pressure plate;

(d) first means for pivotally supporting said pressure plate from saidbase;

(e) a cutting member supported from said plate and extending towardssaid rigid member, said cutting member having a transverse cutting edgethat severs said wire when the insulation thereof is engaged by saidsharpened edges and said pressure plate and cutting member are movedfrom a first position in which said cutting member is outwardly spacedfrom said base to a second position where said cutting member at leastpartially overlaps said forward end surface of said base;

(f) stop means for preventing said cutting edge contacting said rigidmember; and

(g) resilient means that at all times tend to maintain said pressureplate and cutting member in said first position.

2. A portable tool as defined in claim 1 in which said first meansincludes:

(f) a clevis secured to said rigid member;

(g) a transverse pin supported by said clevis; and

(h) a lug aifixed to said pressure plate, with said lug having atransverse opening therein that pivotally engages said pin.

3. A portable tool as defined in claim 2 in which said forward endsurface of said base and at least a part of the rearward surface of saidcutting member are angularly disposed relative to said rigid member andslidably contact one another when said cutting member moves to saidsecond position.

4. A portable tool as defined in claim 3 in which said forward endsurface and said part of the rearward surface have substantially thesame radius of curvature.

5. A portable tool as defined in claim 3 in which said stop means aredefined by forward outer edge portions of 15 said clevis.

6. A portable tool as defined in claim 3 in which said resilient meansis a compressed, helical spring that extends between said base andpressure plate.

References Cited ROBERT C. RIORDON, Primary Examiner 30 R. V. PARKER,1a., Assistant Examiner

